As described in commonly owned German patent document 195 22 019 a head for a floor cleaning machine has a plate rotatable about an upright plate axis and formed offset therefrom with a plurality of downwardly open pockets, respective bearings seated in the pockets, and respective rods rotatable in the bearings about respective tool axes intersecting and forming a very small acute angle with the plate axis. Respective mounting sleeves fixed on the rods are each formed with a plurality of axially downwardly extending and radially deflectable retaining fingers each in turn having an outwardly directed barb. Respective tool elements each have an upper side turned toward the plate and an opposite lower side and are each formed with a central throughgoing hole in turn formed with a downwardly directed shoulder and receiving the respective mounting sleeve with the respective barbs engaged over the shoulder and retaining the respective element on the respective mounting sleeve. Respective seal assemblies on the plate and elements annularly surround each rod.
In such an arrangement it is necessary to periodically replace the tool elements, which can be brushes, polishing disks, or the like. This is done by inverting the tool and pushing in the deflectable fingers so that the tools can be pulled off the rods. Such an operation is carried out in the field normally by the janitorial staff using the equipment.
After some use of the floor machine, however, it is likely that wax, for instance, will fill the hole in the bottom of each tool, packing it tight with a relatively hard substance. Such fouling makes it very difficult to remove the tools, as the retaining fingers have to be pushed inward against this mass. Thus the person changing the tools must clean out the centers of the tools before removing them, making the changeover operation fairly onerous.